This invention concerns protective devices for hollow injection or aspiration needles used in the practice of medicine to carry out injections of fluids into the body or to aspirate body fluids.
Such needles can become contaminated from contact with bodily fluids, and present a risk to medical personnel handling the used needles. It is also desirable to prevent reuse of a needle to prevent transmission of diseases to other patients.
These considerations have led to the development of various injection needle protective devices, as for example the guard shown in U.S. Pat. No. 5,688,241 issued to the present inventor on Nov. 18, 1997 for an Automatic Non-Reusable Needle Guard.
The device described in that patent required removal of the needle from the syringe or other holder for disposal.
U.S. Pat. No. 5,389,085 describes a protector which has the needle mounted to a protective cover so that the needle and cover can be removed together. However, that device does not provide a clear indication that the needle has been used nor positively prevent reuse.
It is the object of the present invention to provide an improved protective device of this type which clearly shows that a needle has been used and positively prevents reuse.
The above recited object and others which will become apparent upon a reading of the following specification and claims are achieved by a protective device for an injection or aspiration needle including an adapter sleeve, which has one end configured to be coupled to a syringe luer lock in place of the needle. The needle is mounted on a hub located within the adapter sleeve to project towards the opposite end of the sleeve. This protective device may be used in a similar manner with an aspiration needle of a multi-sampling system that uses evacuated blood collection vials or tubes.
A barrel piece also included in the device is slidable over the opposite end of the adapter sleeve with an interposed spring urging the barrel piece and adapter sleeve to move apart to a fully extended position and away from a fully nested, retracted position. In an intermediate latched condition, the barrel piece and adapter sleeve are held together resisting the force of the compressed spring by positioning a pair of radially projecting plugs on the adapter sleeve within latching cut outs in each of a pair of slots extending along the barrel piece length. The needle protrudes a short distance from a barrel nose portion with the device in the latched condition indicating an unused condition, and is covered with a cap preparatory to use. In use, as the needle penetrates into the patient""s body, the adapter sleeve is advanced into the barrel piece which is restrained by contact with the patient""s skin. The plugs are moved out of the latching cut outs and down the longitudinal slots until the full needle penetration desired is reached. A reference scale on the barrel piece aids the user in determining when the proper penetration depth has been reached. As the needle is withdrawn from the patients body, the spring causes the adapter sleeve to be withdrawn from the barrel piece, withdrawing the needle into the interior of the barrel piece. The plugs move along the slots until reaching a curved end surface, which cams each of the plugs into respective locking cut outs thereafter preventing axial movement of the adapter sleeve and needle. At this point, the needle tip is retracted completely into the barrel piece.
As the adapter sleeve is rotated to bring the plugs into the locking cut outs, a pair of deflectable strips protruding from the adapter sleeve are rotated into grooves in the barrel piece interior wall, permanently preventing rotation of the adapter sleeve to defeat any attempt to advance the plugs out of the locking cut outs.
The barrel piece has an opening through which the needle passes, and a sloping ridge surrounds the opening to tend to deflect the needle tip away from the opening to provide an additional measure preventing reuse of the needle.
The plugs both have a shape which overlies the edge of the slot through which the plugs slide when moving to the locked position to insure engagement with the slot edges is maintained.